Magnetic nanosensors (MRnS) offer multiple benefits that can be used to design sensitive and robust diagnostic tools. High sensitivity, stability, and ease of surface modification make this approach a strong contender against the more commonly used heat-labile antibodies. Providing picomolar detection ranges, even at higher temperatures where antibodies are impractical, makes MRnS a good replacement for diagnostics in remote locations where specific storage requirements are not available. Amid the most widespread and effective virulent factors affecting humans are bacterial and fungal toxins. Hence, there is a need for sensitive toxin diagnostics that can be used in remote point-of-care locations and reduce the time required for validation of test results.